What are some general guidelines when creating Garmin Custom Maps?

Certain guidelines need to be followed to insure Garmin Custom Maps will display on the device. Some guidelines to remember when creating Garmin Custom Maps are:

More than one jpeg can preside in a kmz file.

The only kml file that will be processed is a doc.kml, inside the kmz file

Jpegs files are the only supported image type

Jpeg must be saved without Progressive Image (typically found under advanced option).

Kmz files are read from \Garmin\CustomMaps directory on both the unit's internal memory and on the SD Card.

Images over 1 mega pixel (1024x1024 pixels, 512x2048 pixels, etc.) will be rendered at a reduced resolution on the unit. If this is causing a problem for your map, you can split the image and use multiple jpegs inside of one kmz file.

Each jpeg should be less than 3MB.

The max number of Custom Map JPEG images that can be loaded:

Typically 100 for supported devices

Exceptions:

Montana (500)

Monterra (99)

Oregon 600 series (500)

GPSMAP 64 series (500)

The size of the jpeg files will affect the draw speed on the Garmin device

There is no limitation on kmz file size as long as the previous limitations are met

Since each kmz file will need at least one jpeg file to be a functional custom map, kmz file limitations match jpeg limitations

Custom Maps are enabled or disabled as a group

Following these guidelines in the creation of Garmin Custom Maps will insure they work correctly on the device.